This invention relates generally to a tool for cutting objects requiring a substantial force to achieve the cutting thereof. More particularly, the invention relates to a portable cutter tool for general use at an emergency scene, such as an automobile accident, for extricating a victim trapped in the automobile.
There is a need in the emergency rescue field for a cutter tool that is portable, compact, powerful, lightweight, self-contained and that can be operated quickly and easily. Furthermore, there is a specific need for a portable cutter tool that can be used at an accident scene to extricate a victim that is trapped in place by the foot pedals and/or steering wheel of the vehicle. The present-day tools used for this type of emergency operation are not entirely satisfactory. A major problem with these present-day cutter tools is their excessive weight and size and their lack of the maneuverability necessary to quickly and easily extricate a victim trapped in an automobile wreck, by the foot pedals and/or the steering wheel thereof.
It is the general object of the invention to provide an improved portable cutter tool for use at an emergency scene that is more compact, is lighter in weight, safer and has improved maneuverability as well as being easy to manufacture and service in the field.
To this end, the portable cutter tool of the invention has the ability to maneuver into tight locations, such as the location of the foot pedals and the steering wheel of an automobile, and to make the needed cuts to free a trapped victim. The improved maneuverability of the cutter tool of the invention results from the provision of a swivel assembly comprising a swivel, a seal and an end cap for connecting the hose for the operating fluid to the housing for the cutter which housing contains the piston and cutter blades actuated by the pumping of the operating fluid. More specifically, the swivel assembly includes an outlet connection which extends at 45.degree. to the cutter housing. This 45.degree. outlet connection improves the maneuverability of the cutter tool by allowing the hose to swing out of the way as the housing is maneuvered into a cutting position. Since the hose has a rigid reinforcement at the end whereat it is connected to the housing, it is very important to be able to rotate the hose to change the direction at which it joins with the cutter housing without moving the hose or increasing the effective length of the tool.
The compactness of the portable cutter tool of the invention is enhanced by the provision of a cutter housing that is made of a single-piece integral cylinder and head. This construction eliminates the need for an interface connection between the required cylinder and a housing and thereby results in a more compact and lighter weight tool. Moreover, an integral piston stop is provided in the head which eliminates the need to step the piston or create a stop in the cylinder. The stop is necessary to avoid overextension of the piston and possible hydraulic fluid loss if the blades, which are the primary piston stop, are removed or broken for some reason. Also, this single-piece construction of the cylinder and head permits the use of an unchanging cylinder bore for providing both the stop and the cylinder for the actuating piston. In addition, a cast groove is provided in the single piece housing to eliminate the need to cut a groove for a piston wiper, which makes the final machining of the housing quicker and easier. Another feature of the housing design is the provision of cast ribs which strengthen the cylinder and aid in the holding and positioning of the tool during cutting.
The compactness of the cutter is also enhanced by a piston design which results in a compact cylinder construction. To this end, there is provided a return spring which is incorporated within the interior of a hollow piston to thereby reduce the length of the cylinder while not affecting the piston diameter. Furthermore, the piston does not have to be provided with a step since the housing has a stop incorporated into it.
Another feature of the invention is the improved cutter blade or tip design. To this end, the cutter blade is designed to provide two identical cutter tips for both sides of the cutting area. By means of a simple rotation, the moving cutter tip could be replaced with the stationary tip if desired. Furthermore, the cutter tips have a compound angle which provides a strong tip and a gradual cutting angle that acts to provide relief and reduce the force required to perform a cut. Also, a tab is provided on the tip to keep a tip engaged in a guide slot therefor throughout the entire cutting movement. Also, a molybdenum-based coating is added to the tips for lubrication and corrosion protection from the elements.
Another feature of the invention is the provision of a self-contained tool which includes a pump and housing assembly capable of operating as a 10,000 psi system to produce a powerful cutter. There is provided a hand pump of the single stroke type wherein only eighty pounds of handle force can generate 10,000 psig of hydraulic pressure.
Another feature of the invention is to provide for safe operation whereby the cutter tool cannot be improperly connected or assembled. To this end, the outlet connection for the swivel and both the hose and the pump are provided with lefthand threads so that the pump and the hose cannot be connected to any other tool which could result in an unsafe operating situation.
The head portion of the cutter housing is constructed to provide a wide support area near the cutter tips. This construction serves to limit the angle that a part to be cut can take relative to the cutter tips whereby the possibility that the cutter will slip relative to the part during the cutting movement is minimized.